Predicting adverse outcome with exercise SPECT technetium-99m sestamibi imaging in patients with suspected or known...

The goal of this study was to determine the ability of exercise single-photon emission computed tomographic (SPECT) technetium-99m (Tc-99m) sestamibi imaging to predict adverse events in a population with a comparable distribution of men (n = 114) and women (n = 115). Consecutive patients referred for evaluation of chest pain syndrome, known coronary artery disease, or residual ischemia after acute myocardial infarction underwent imaging using a single-headed SPECT camera. Clinical readings were reviewed and scored by independent observers as normal or abnormal. Follow-up, defined as time from scanning until an event, late revascularization, or patient response averaged 19.2 +/- 5.2 months and was 90% complete (229 of 255 patients). Cardiac death and nonfatal infarction were corroborated by chart review or physician contact. Patients were excluded from analysis if a revascularization procedure was performed within 1 month of imaging. There were 172 patients with normal scans (67%) and 83 with abnormal scans (33%). Of the patients in whom followup was obtained, 2 of 155 with normal scans (0.8%/year) and 6 of 74 with abnormal scans (5.4%/year) had cardiac events. Statistical analysis using the Kaplan-Meier survival curves suggests a significant difference in event-free survival between normal and abnormal scans. Patients with abnormal scans portended a worse outcome (chi-square = 8.04, p <0.005). Thus, exercise SPECT Tc-99m sestamibi scintigraphy is useful for prognostication in a mixed population of patients with suspected or known coronary artery disease in which women comprised 50% of the patient cohort.